1. Field
This disclosure generally relates to powering and/or controlling devices, for example medical devices, for instance transdermal delivery devices.
2. Description of the Related Art
Medical devices that employ electromotive forces are well known in the art. For example, iontophoretic drug delivery devices employ an electromotive force and/or current to transfer an active agent (e.g., a charged substance, an ionized compound, an ionic drug, a therapeutic, a bioactive-agent, and the like), to a biological interface (e.g., skin, mucus membrane, and the like), by using a small electrical charge applied to an iontophoretic chamber containing a similarly charged active agent and/or its vehicle.
Iontophoresis devices typically include an active electrode assembly and a counter electrode assembly, each coupled to opposite poles or terminals of a power source, for example a chemical battery or an external power station connected to the iontophoresis device via electrical leads. Each electrode assembly typically includes a respective electrode element to apply an electromotive force and/or current. Such electrode elements often comprise a sacrificial element or compound, for example silver or silver chloride. The active agent may be either cationic or anionic, and the power source may be configured to apply the appropriate voltage polarity based on the polarity of the active agent. Iontophoresis may be advantageously used to enhance or control the delivery rate of the active agent. The active agent may be stored in a reservoir such as a cavity. Alternatively, the active agent may be stored in a reservoir such as a porous structure or a gel. An ion exchange membrane may be positioned to serve as a polarity selective barrier between the active agent reservoir and the biological interface. The membrane, typically only permeable with respect to one particular type of ion (e.g., a charged active agent), prevents the back flux of oppositely charged ions from the skin or mucous membrane.
Commercial acceptance of iontophoresis devices is dependent on a variety of factors, such as cost to manufacture, shelf life, stability during storage, efficiency and/or timeliness of active agent delivery, biological capability, and/or disposal issues. Commercial acceptance of iontophoresis devices is also dependent on their versatility and ease-of-use. Therefore, it may be desirable to have novel approaches for powering iontophoresis devices.
The present disclosure is directed to overcoming one or more of the shortcomings set forth above, and providing further related advantages.